Further attempts will be made to define the temporal aspect of the LH surge. Studies will be instituted in pubertal subjects to elucidate ontogenetic relationships of the 24-hour LH secretory pattern. In patients with amenorrhea, we will analyze their LH secretory programs and attempt to correlate them with the other clinical findings. A study of the effect of L-dopa on LH release is planned in two different phases of the menstrual cycle.